Former astronaut Buzz Aldrin may have helped “Dancing with the Stars” nab its highest debut ratings when he did the Moonwalk on the show’s March 22 season opener, but it still pales in comparison with NASA’s broadcast of the first manned moon landing — which also co-starred the Apollo 11 moonwalker.

The TV dance competition averaged about 23.9 million total viewers during its two-hour season premiere — the show’s best debut yet — making it ABC’s second-most-watched show ever for its time slot behind the 2001 Rose Bowl, according to overnight Nielsen ratings reported by Media Life Magazine.

But that number is dwarfed by the estimated 500 million people around the world who watched Aldrin and fellow Apollo 11 astronaut Neil Armstrong land and walk on the Moon during their July 1969 mission.

Like “Dancing with the Stars,” the Apollo 11 mission also had a record debut. About 1 million people were estimated to watch the astronauts blast off atop a massive Saturn 5 rocket July 16, 1969. At the time, it was the most-watched launch in NASA history, the space agency said.

“In the 8-day mission, the TV networks beamed abroad, via satellite, telecasts totaling 230 hours,” according to a NASA account of the Apollo 11 mission.

Aldrin and Armstrong flew to the Moon with crewmate Michael Collins, who remained in lunar orbit aboard the command module Columbia during the historic first Moon landing. Of course, the Apollo 11 mission — the first of NASA’s six manned Moon landings between 1969 and 1972 — lasted just over one week. The 2010 season of “Dancing with the Stars” will run for 10 weeks.

But whether the 80-year-old Aldrin will stay in the running that long is up to his performance and the whim of American TV audiences. He is teamed up with professional dancer Ashly Costa, though their first cha-cha received the lowest score of the night from the show’s judges.

“My primary motivation for joining the show is to help bring NASA and the U.S. human spaceflight program to the front of popular consciousness,” Aldrin said in a NASA statement released March 23. “‘Dancing with the Stars’ has an audience of millions of followers and it would be great if those viewers became supporters of our space program. I’m hoping that all of my old friends and colleagues in the space community can tune in and cast their vote for the octogenarian on the dance floor!”